I posted a query on the Foras na Gaeilge web site wondering what the irish for biochar would be and i am told it is Bithghualach which roughly translate to 'bio charcoal'.

Now you can have nice cup of tea and some charcoal and they taste nice!
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Lawrence D. Hills book 'Month by Month Organic Gardening,The Green Gardeners Calender' first published in 1971 is considered a bible for organic gardeners and growers. It well worth having on ones book shelf as a reference book. The pdf file below  is from pages 34 and 35 of 1989 edition and he talks about using wood ash in the chicken house and he goes as far as saying ''It is worth keeping chickens, if you have a wood stove,to get fertilizer". Remember part of the wood ash will be made of carbonized wood ie charcoal.